Air cleaner



May 15, 1928. 1,669,413

' F A. DONALDSON AIR CLEANER Filed Oct. 16, 1924 Patented Ma is, 1928.

UNITED STA res PATENT orrlca.

FRANK A. DONALDSON', OF MTNNEAPOLIS, MINNESOTA.

. AIR CLEANER Application filed October 16, 1924. Serial No. 743,981.

are particularly applicable to air cleaners of the dust collector type.

The invention is illustrated in the single view of drawing, which view is partly in side elevation and partly in vertical section and has some parts broken away.

Preferably,,the casing or body shell of the air cleaner is a thin sheet metal cylinder 1 provided at one end with an annular head 2 and at its other end withian inset rigidly secured circumferentially spaced series of spiral vanes or blades 3 that cause the air drawn into the casing to take up a whirling motion. These vanes 3 are soldered or otherwise secured to the casing and, at the axis of the casing, they are overlapped in such a way that, around the axis of the shell, air cannot pass axially on a straight line into the casing.

The interior of the casing 1 is divided by a suitable partition structure into a separating chamber A, a clean air chamber B,

and a dust chamber C. In this construction, said partition structure comprises an axial tube 4 and an annular partition 5. The tube 4 is of considerably less diameter than the cylinder 1, is rigidly secured to the an 'nular head 2, and projects into the cylinder 1 concentrically therewith. The annular partition 5 is soldered orotherwise rigidly secured to the inner endportion of the tube 4 and to the interior of the cylinder 1. The air. and dust-separating chamber A is formed within the cylinder 1, between the blades 3 and the inner extremity of the tube 4, the clean air chamber B is formedwithi'n'the sleeve 4, and the dust .chamber G is formed within the cylinder 1, around the sleeve 4 and between the annular head 2 and annular partition 5. Allof the parts are thus brought into very compact arrangement within a single shell or cylinder. The extreme inner end of the tube 4: aflords a clean air discharge port from the separating chamber A and is concentric to the axis of the cylinder. Theannular partition 5 is preffor a' considerable area,

erably of truncated conical form, flaring backward or toward the head 2. The dust collar described is especially adapted to be operated when the cylinder 1 is set on an approximately horizontal axis, and in such arrangement, the partition 5, at its uppermost portion or adjacent to the top of the cylinder 1, is provided with an eccentric-ally located dust discharge port 6 that opens from the separating chamber A into the dust chamber C. This port 6 is formed by partly severing and pressing a portion or the partition 5 slightly into the dust chamber The dust chamber C is provided atv its bottom with a large discharge port 7 formed by a hole in the bottom of the cylinder 1, and this discharge port, as shown, is extended by a funnel-shaped flange 8'secured to the bottom of the cylinder. This flange 8 forms a sort of extension of the dust chamber 6, as well as an extension of the discharge port, and to open and close the same, there is provided a quite large valve head 9 shown as secured to the intermediate portion of a lever 10 pivoted at one end to a lug 11 depending from the bottom of the cylinder 1.

The tube 4, as shown, is extended beyond or outward ot'the head 2 and is adapted to .be telescoped into the air-receiving end of the carburetor a for the delivery of the clean air to the'carburetor.

As a simple and eflicient means for automatically operating the valve *9 to close the dust discharge port when the "engine is in action and to open the same when the engine is idle, I provide a section-controlled valve actuator preferably comprising a cylinder. 12 and cooperating piston 13, said cylinder being fixed in respect to the carburetor and the depending stem of said piston being connected to the free end of the valve lever 10. As shown, a light coiled spring 14, applied around the piston stem, reacts against the lower cylinder head and against said stem and assists gravity in nor mally holding the piston 13 and valve 9 lowered, as shown in the drawings. The lower end of the cylinder 12 should be subject only to atmospheric pressure and, hence, said cylinder is shown as provided with a small air passage 15: The carburetor a may be of any suitable type and is connected in the customary way to the intake end of an intake manifold b, which-latter is connected by a small pipe 16 to the top of the cylinder 12.

into the open end of 3, will be caused to take up Before describing in detail the operation of the air cleaner proper, attention is called to the fact that, when the engine is in action, the suction produced in the intake manifold will produce a partial vacuum or suction in' the upper portion of the cylinder 12, and that this will cause the piston 13 to rise and hold the valve 9 against the funnel flange 8, thereby closing the dust discharge port or passage in the bottom of the dust chamber C. This condition will prevail as long as the engine is in action, but the instant that the engine stops and the suction ceasesin theintake manifold,

the gravity, assisted by the spring 14, will lower the piston, thereby dropping the valve 9 to open position and permitting the dust to run freely out of the dust chamber C. The dust chamber is, therefore, automatically cleaned each time that the engine stops.

Under the suction produced in the carburetor while the engine is in action, partial vacuum will, of course, be maintained in the clean air chamber B and, hence, in the separating chamber A, so that the dustladen air from the exterior will be,drawn the chamber A and, by the spiral vanes a whirling motion within said separating ticles through the dust chamber.v 'This whirling motion will cause the heavier particles, such as dust, to be thrown against the cylindrical wall of the tube land totake against the annular partition 5, so that the dust, on reaching the dust port 6, will be thrown intothe dust chamberB. In this action, gravity is not relied upon to separate the dust from the air, but-,on the contrary,

the separation is made somewhat against the action of gravity and by centrifugal force, which throws or port 6 into. the dust chamber C, While the air freed therefrom will pass through the axial air outlet port into the clean air chambeImB and from thence to the carburetor. i

As is evident, dust may accumulate in the dust chamber C until it completely surrounds the tube 4 and substantially fills said up a whirling motion whirls the dust pa rdust chamber. Such an arrangement makes it possible to keep the entire dust chamber within, the cylindrical shell. -Of course, this annular dust chamber can be utilized to the full value above stated only when the cylindrical shell of the carburetor is set approximately on a horizontal axis. cleaner'described is not only compact and eilicient, but may be made at comparatively small cost.

It will be noted that the air cleaner is connected to the intake of the carburetor and that the suction pipe 16 of the suction actuated valve-operating device, made up of the cylinder and piston, intake manifold, that is, to the fuel intake conduit between the carburetor and the engine. By this manner of connection, the valve-operating'device is dependent for its action not on the on the suction orvpaptial vacuum produced in the intake manifold. The suction in the intake manifold must always be somewhat greater than the suction produced in the air cleaner and is much greater when the throttle valve is partially closed, hence the importance of connecting the air cleaner to the receiving side of the carburetor and connecting the suction pipe of the valve actuator with the delivery side of said carburetor.

What I claim is:

The combination with a carburetor having an air intake and a vapor discharge conduit, the latter of which is adapted for con- 'nection to the intake of an internal combustion engine, of an air cleaner connected to the intake of said carburetor and comprising a shell having a dust discharge port, a valve (for opening and closing said port, and a suction-operated valve operator having a suction tube connected to the vapor discharge port of said carburetor, said valve operator normally holding said valve in a port-opening position but holding said valve in a portcloslng position when the vapor delivery conduit of said carburetor is subjected to suction or partial vacuum. I

In testimony whereof I afiix my signature.

FRANK A. DONALDSON.

is connected to the The air- 

